The invention relates to an image recording apparatus for recording an image on a sheet while transporting the sheet from a sheet feeding section to a sheet output section.
A duplex image recording apparatus is a type of image recording apparatus, which is used for recoding an image on both sides of a sheet.
JP 2003-104613A discloses a duplex image recording apparatus provided with a re-transport path and a reversing transport path. The re-transport path connects a first portion of a main transport path (which leads from a sheet feeding section to a sheet output section through an image recording section) positioned between the image recording section and the sheet output section, to a second portion of the main transport path positioned between the sheet feeding section and the image recording section. The reversing transport path, which branches out from a portion of the re-transport path, is used for transporting a sheet in forward and backward directions therein.
After a sheet has an image recorded on a first side, a leading end and a tail end of the sheet are reversed in the reversing transport path. Thus, the sheet is transported to the image recording section, with a second side facing the image recording section.
There is another type of image recording apparatus having the functions of performing face-up output process and face-down output process. In the face-up output process, a sheet is output to a sheet output section with an image-recorded side facing upward, and in the face-down output process, a sheet is output with an image-recorded side facing downward.
In a copying operation where an image of original document is to be copied on a sheet of paper, an operator is around the apparatus and, thus, can check the copied sheet if the sheet is output face-up to the sheet output section. When an image is to be recorded on a sheet according to image data received through a network from a terminal device, an operator is not around the apparatus. Thus, a sheet can be output face-down so that an image recorded thereon may not be readily seen by others. In this type of image recording apparatus, a sheet is turned upside down by reversing a leading end and a tail end of a sheet in a portion of a main transport path positioned between an image recording section and the sheet output section. A sheet is selectively reversed upside down after passing through the image recording section, so that the sheet is selectively output to the sheet output section with an image-recorded side facing upward or downward.
In order to incorporate the function of reversing a sheet into duplex image recording apparatus, an additional sheet transport path is required that leads from a reversing transport path to a sheet output section. Also, a plurality of bifurcations are required to be provided in the main transport path, the re-transport path, and the reversing transport path. However, the additional transport path may cause the apparatus to be upsized and therefore to take a longer time to transport a sheet therein. Also, a sheet jam is more likely to occur in the bifurcations. Furthermore, random arrangements of the bifurcations complicate a process of removing a jammed sheet.
A feature of the invention is to provide an image recording apparatus with the functions of duplex image recording and reverse sheet output, that includes a main transport path, a re-transport path, a reversing transport path, and a plurality of bifurcations, positioned in optimum arrangements that prevent the apparatus from being upsized, a sheet transport time from taking long, and a process of removing a jammed sheet from being complicated.